1. Field of Invention
The present invention relates to sutures for use in surgery.
2. Description of the Prior Art
Sutures of silk have long been known and used for various surgical applications. Conventional sutures are of various types and include those prepared by twisting, braids formed by plaiting, and braids having a core. The known suture is made of silk only and therefore has the drawback of being low in stiffness and having very poor ability to restore itself when deformed. For example, the suture wound on a reel remains helically curled when unwound therefrom and is difficult to straighten to a corrected form. The same difficulty is also encountered with the suture wound around a paper core.
If the suture used is as curled the suture will coil around the arm or hand of the surgeon or hang down in a helical form due to its excessive flexibility and causes great frustration to the surgeon.
To overcome this problem, we have proposed a suture comprising a core of synthetic fiber filament yarn and a braid or the like of silk strands covering the core (Japanese Utility Model Application No. 41670/1987). The proposed suture is given suitable flexibility due to the appropriate rigidity of the filament yarn as afforded by doubled polyester filament strands in combination with the flexibility of the silk strands covering the yarn, whereby the suture is made amenable to the correction of its deformation such as the curl due to winding so as to be easily handled. Furthermore, the suture has a higher breaking strength than those consisting solely of silk strands owing to the presence of the core of synthetic fiber filament yarn. However, the suture still remains to be improved since there is a demand for sutures having higher strength.